diff options
| -rw-r--r-- | include/linux/bitmap.h | 18 | ||||
| -rw-r--r-- | kernel/events/core.c | 5 |
2 files changed, 21 insertions, 2 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 598bc999f4c2..3b77588a9360 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -339,6 +339,24 @@ static inline int bitmap_parse(const char *buf, unsigned int buflen, return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits); } +/* + * bitmap_from_u64 - Check and swap words within u64. + * @mask: source bitmap + * @dst: destination bitmap + * + * In 32-bit Big Endian kernel, when using (u32 *)(&val)[*] + * to read u64 mask, we will get the wrong word. + * That is "(u32 *)(&val)[0]" gets the upper 32 bits, + * but we expect the lower 32-bits of u64. + */ +static inline void bitmap_from_u64(unsigned long *dst, u64 mask) +{ + dst[0] = mask & ULONG_MAX; + + if (sizeof(mask) > sizeof(unsigned long)) + dst[1] = mask >> 32; +} + #endif /* __ASSEMBLY__ */ #endif /* __LINUX_BITMAP_H */ diff --git a/kernel/events/core.c b/kernel/events/core.c index ca4fde5ed268..849919c2f3d7 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5340,9 +5340,10 @@ perf_output_sample_regs(struct perf_output_handle *handle, struct pt_regs *regs, u64 mask) { int bit; + DECLARE_BITMAP(_mask, 64); - for_each_set_bit(bit, (const unsigned long *) &mask, - sizeof(mask) * BITS_PER_BYTE) { + bitmap_from_u64(_mask, mask); + for_each_set_bit(bit, _mask, sizeof(mask) * BITS_PER_BYTE) { u64 val; val = perf_reg_value(regs, bit); |